the rectangular backplate above the bowed railed basket with a reeded apron, the hob-fronts cast in relief with a crown-topped wreath centred with the regal monogram "IV WR", and bearing the "broad arrow" mark between "B.O." for "Board of Ordnance" - the mark of the Royal Ordnance,

The history of this hob grate design isn’t known. We assume to be a limited issue for perhaps a barracks  – a regiment with a royal connection to William IV (1830-1837) perhaps..

The “Broad Arrow” mark is an established mark dating from the 14th Century onwards to indicate that an object is property of the crown. Here accompanied with “B.O” for Board of Ordnance. The broad arrow has a particular prevalence in marking property of the Royal Ordnance Departments – supplying munitions to the Navy – but into the 20th Century and the two world wars had prolific usage more broadly marking Ministry of Defence property. The mark, whose origins are heraldic can be seen on MoD tools, Royal Ordnance stone markers, trees protected by the crown and, in times gone by, prisoners’ uniforms.